Study finds noninvasive prenatal screening using low-cost whole genome sequencing can identify mothers at risk for transmitting virus that causes hearing loss in newborns.
Noninvasive prenatal screening performed with low-cost whole genome sequencing can detect pregnant mothers at risk for transmitting cytomegalovirus (CMV) to their developing babies, according to new research published in Clinical Chemistry.
The findings could help doctors identify which pregnant patients would benefit from receiving antiviral treatment to prevent mother-to-fetus transmission of CMV, a common herpes infection that can cause permanent hearing loss and other complications in newborns, according to researchers.
CMV occurs in about 1 in 150 live births globally and can trigger neurodevelopmental delays and other irreversible problems in up to 20% of infants born with the infection. Current guidelines do not recommend prenatal screening for CMV, largely because effective therapies have not been widely available.
However, research from 2020 showed the antiviral drug valacyclovir can reduce CMV transmission by more than 70% when given to infected women in their first trimester of pregnancy. While the FDA has not formally approved valacyclovir for this use, many doctors prescribe it to pregnant patients known to have CMV. The new study provides evidence that noninvasive prenatal screening—which is already routinely used during pregnancy to detect chromosomal abnormalities—can also gauge CMV infection in both mother and baby.Â
Large-Scale Analysis of Screening Data
Researchers from Belgium led by Dr Geert A Martens analyzed noninvasive prenatal screening data from 22,333 pregnancies at 12-14 weeks’ gestation between November 1, 2019, and January 1, 2025. Noninvasive prenatal screening was performed using low-pass whole genome sequencing, a cost-effective method that assesses a patient’s genetic blueprint.
The research team evaluated blood samples for free-floating fragments of DNA from CMV found among genetic material from non-human sources like viruses and bacteria.
They found CMV DNA in 2.1% (462) of the pregnancies studied. The researchers divided those patients’ blood samples into four groups based on the amount of viral DNA detected, ranging from least to most, and validated this information by comparing it to results using PCR, the gold-standard method for measuring DNA.
Strong Diagnostic Accuracy
The results showed that the noninvasive prenatal screening-derived CMV data demonstrated good diagnostic accuracy for maternal and newborn CMV infections. A positive CMV result was a strong indicator of infection among mothers, confirmed by antibody testing, and their newborns, confirmed through a systematic screening program. The risk for maternal and congenital CMV infection was highest in blood samples from pregnancies with the most CMV DNA.
“Crucially, our study is the first to directly link [noninvasive prenatal screening]-derived CMV read counts to both maternal serostatus and confirmed cCMV [congenital CMV] outcomes from a systematic newborn screening program, in a real-world high-volume setting of first-tier cell-free fetal DNA screening,” the researchers stated.
The authors noted that while more research is needed to determine the clinical significance of the findings, the results are promising for integration into routine pregnancy screening.
“Given its low cost and high throughput, [the integration of CMV DNA testing] into routine aneuploidy screening is a powerful complement to serology, poised to improve the identification of pregnancies that may benefit from antiviral therapy to prevent cCMV,” the authors wrote.
The study was published in a special issue of the Association for Diagnostics & Laboratory Medicine’s Clinical Chemistry focused on perinatal diagnostics.
ID 48802990 © Subbotina | Dreamstime.com
